davidwolfpaw · August 23, 2016 19:06 · Aug 23, 2016
diff --git a/dynamic_date_dropdown_gravityforms.php b/dynamic_date_dropdown_gravityforms.php
@@ -0,0 +1,118 @@
+<?php
+/*
+ * Dynamically generate list of dates in Gravity Forms Dropdown and remove past and previously selected dates
+ */
+
+
+add_filter( 'gform_pre_render', 'dl_populate_dropdown' );
+
+//Note: when changing drop down values, we also need to use the gform_pre_validation so that the new values are available when validating the field.
+add_filter( 'gform_pre_validation', 'dl_populate_dropdown' );
+
+//Note: when changing drop down values, we also need to use the gform_admin_pre_render so that the right values are displayed when editing the entry.
+add_filter( 'gform_admin_pre_render', 'dl_populate_dropdown' );
+
+//Note: this will allow for the labels to be used during the submission process in case values are enabled
+add_filter( 'gform_pre_submission_filter', 'dl_populate_dropdown' );
+
+function dl_populate_dropdown( $form ) {
+
+    // Set Form ID and field ID to 6 and 4 respectively
+    $form_id = 6;
+    $field_id = 4;
+
+    //only populating drop down for form id 6
+    if ( $form['id'] != $form_id ) {
+       return $form;
+    }
+
+
+    // Create array of available dates (Updated Manually until I think of something better)
+    $dates = array(
+        '20 August 2016',
+        '21 August 2016',
+        '22 August 2016',
+        '23 August 2016',
+        '24 August 2016',
+        '25 August 2016',
+        '26 August 2016',
+        '2 September 2016',
+        '16 September 2016',
+        '23 September 2016',
+        '30 September 2016',
+        '14 October 2016',
+        '21 October 2016',
+        '28 October 2016',
+        );
+
+
+    // Create array for Unix timestamped dates
+    $unix_dates[] = array( 'text' => '', 'value' => '' );
+
+
+    // Convert dates to array of Unix timestamps (I don't want to do this myself!)
+    foreach ( $dates as $date ) {
+        $unix_dates[] = array( 'value' => strtotime( $date ), 'text' => $date );
+    }
+
+    // Get the past 20 entries to this form to compare and remove used dates
+    $entries = GFAPI::get_entries( $form_id );
+
+    // Create array of booked dates
+    $booked_dates = array();
+    foreach ( $entries as $entry ) {
+        $booked_dates[] = ( $entry[ $field_id ] );
+    }
+
+    // Update array to remove any dates that have been booked already
+    foreach ( $unix_dates as $unix_date => $date_value ) {
+
+        foreach ( $date_value as $key => $value ) {
+
+            foreach ( $booked_dates as $booked_date ) {
+
+                // If the date is booked, remove it from the list
+                if ( ( $key == 'value' ) && ( $value == $booked_date ) ) {
+                    unset( $unix_dates[$unix_date] );
+                }
+
+            }
+
+        }
+
+    }
+
+    // Get current Unix timestamp
+    $current_time = time();
+
+    // Update array to remove any dates that have passed or will pass in 12 hours
+    // I want to only allow people to schedule up to noon the day before to avoid surprises
+    foreach ( $unix_dates as $unix_date => $date_value ) {
+
+        foreach ( $date_value as $key => $value ) {
+
+            // Current time plus twelve hours
+            $time_plus_twelve = $current_time + (60*60*12);
+
+            // See if time has passed, and if so, unset date
+            if ( ( $key == 'value' ) && ( $time_plus_twelve >= $value ) ) {
+                unset( $unix_dates[$unix_date] );
+            }
+
+        }
+
+    }
+
+
+    // Adding items to field
+    foreach ( $form['fields'] as &$field ) {
+
+        if ( $field->id == $field_id ) {
+            $field->choices = $unix_dates;
+        }
+
+    }
+
+
+    return $form;
+}